Acid catalyst composition comprising halide-containing conjunct polymer and lewis acid

ABSTRACT

An acid catalyst effective for a conversion of a hydrocarbon, comprising: greater than 15 wt % halide-containing conjunct polymer, and a Lewis acid; wherein less than 0.1 wt % solid precipitates from the catalyst when it is held for three hours or longer at 25° C. or below.

This application is a division of prior application Ser. No. 13/228,171,filed Sep. 8, 2011, and published as US 2012-0004095A1, hereinincorporated in its entirety. The assigned art unit of the prior parentapplication is 1732.

This application is also a division of prior application Ser. No.12/335,476, filed Dec. 15, 2008, and published as US 2010-0152506 A1,herein incorporated in its entirety. The assigned art unit of the priorparent application is 1732.

This application also claims the benefit as a continuation to twopreviously co-filed patent applications titled “IONIC LIQUID CATALYSTHAVING A HIGH MOLAR RATIO OF ALUMINUM TO NITROGEN,” published as US2010-0152027 A1, and “PROCESS TO MAKE A LIQUID CATALYST HAVING A HIGHMOLAR RATIO OF ALUMINUM TO NITROGEN,” published as US 2010-0152518 A1,herein incorporated by reference in their entireties.

This application is also a continuation to a previously co-filedapplication titled “A METHOD TO MAKE AN ACID CATALYST HAVING GREATERTHAN 20 WT % CONJUNCT POLYMER”, published as US 2011-0319258 A1, hereinincorporated by reference in its entirety.

This application is related to a co-filed application titled “AN ACIDCATALYST COMPOSITION COMPRISING CONJUNCT POLYMER AND LEWIS ACID” hereinincorporated in its entirety.

FIELD OF THE INVENTION

This invention is directed to an acid catalyst composition, that iseffective for conversion of a hydrocarbon, having greater than 15-20 wt% conjunct polymer.

DETAILED DESCRIPTION OF THE INVENTION

In one embodiment, a process for hydrocarbon conversion, comprising:contacting a hydrocarbon with an acid catalyst containing greater than15 wt % conjunct polymer is provided; wherein the acid catalyst has amolar ratio of Al to a heteroatom selected from the group of N, P, O, S,and combinations thereof greater than 2.0; and wherein the hydrocarbonis converted during the contacting.

In another embodiment, a method to make a catalyst is provided,comprising: mixing aluminum chloride in the presence of a hydrocarbonsolvent and an organic chloride and optionally an ionic liquid; wherebythe resulting acidic ionic liquid catalyst has greater than 15 wt %conjunct polymer and has a molar ratio of Al to a heteroatom selectedfrom the group consisting of N, P, O, S, and combinations thereofgreater than 2.0. The resulting ionic liquid catalyst is effective forcatalyzing a reaction.

Additionally, there is provided an acid catalyst composition, comprisinggreater than 15 wt % conjunct polymer and having a molar ratio of Al toa heteroatom selected from the group consisting of N, P, O, S, andcombinations thereof greater than 2.0. The catalyst is effective for aconversion of a hydrocarbon.

Also, an acid hydroconversion catalyst is provided, comprising greaterthan 15 wt % halide-containing conjunct polymer and a Lewis acid;wherein less than 0.1 wt % solid precipitates from the catalyst when itis held for three hours or longer at 25° C. or below.

Definitions:

The term “comprising” means including the elements or steps that areidentified following that term, but any such elements or steps are notexhaustive, and an embodiment may include other elements or steps.

The term “effective for catalyzing a reaction” means that a commerciallysufficient amount of a hydrocarbon is converted by a reaction. The term“effective for conversion of a hydrocarbon” also means a commerciallysufficient amount of the hydrocarbon is converted. For example, in anisoparaffin/olefin alkylation this could be greater than 75 wt %conversion of an olefin, greater than 85 wt % conversion of an olefin,greater than 95 wt % conversion of an olefin, or up to 100 wt %conversion of an olefin. The commercially significant amount can varysubstantially depending on the hydrocarbon being converted and the valueof the converted product that is produced.

The term conjunct polymer was first used by Pines and Ipatieff todistinguish these polymeric molecules from typical polymers. Unliketypical polymers which are compounds formed from repeating units ofsmaller molecules by controlled or semi-controlled polymerizations,“conjunct polymers” are “pseudo-polymeric” compounds formedasymmetrically from two or more reacting units by concurrentacid-catalyzed transformations including polymerization, alkylation,cyclization, additions, eliminations and hydride transfer reactions.Consequently, the produced “pseudo-polymeric” may include a large numberof compounds with varying structures and substitution patterns. Theskeletal structures of “conjunct polymers”, therefore, range from thevery simple linear molecules to very complex multi-feature molecules.

Some examples of the likely polymeric species in conjunct polymers werereported by Miron et al. (Journal of Chemical and Engineering Data,1963), and

Pines (Chem. Tech, 1982). Conjunct polymers are also commonly known tothose in the refining industry as “red oils” due to their reddish-ambercolor or “acid-soluble oils” due to their high uptake in the catalystphase where paraffinic products and hydrocarbons with low olefinicityand low functional groups are usually immiscible in the catalyst phase.In this application, the term “conjunct polymers” also includes ASOs(acid-soluble-oils), red oils, and C12+ polyal kylates.

In one embodiment the acid catalyst is a solid. Examples of solid acidcatalysts are supported catalysts, supported Lewis acid catalysts,H-form zeolites, mass sulfated zirconia catalysts, zirconium oxidecatalysts, solid phosphoric acid catalysts, crystalline tin oxide,supported sulfonic acids, and heteropoly acids.

In one embodiment the acid catalyst is a liquid. Examples of liquidcatalysts are sulfuric acid or hydrofluoric acid. In another embodimentthe liquid acid catalyst is an ionic liquid catalyst.

Ionic Liquid Catalyst:

“Ionic liquids” are liquids whose make-up is comprised of ions as acombination of cations and anions. The most common ionic liquids arethose prepared from organic-based cations and inorganic or organicanions. Ionic liquid catalysts are used in a wide variety of reactions,including Friedel-Crafts reactions.

The ionic liquid catalyst is composed of at least two components whichform a complex. To be effective at alkylation the ionic liquid catalystis acidic. The ionic liquid catalyst comprises a first component and asecond component. The first component of the catalyst will typicallycomprise a Lewis acid compound selected from components such as Lewisacid compounds of Group 13 metals, including aluminum halides, alkylaluminum halide, gallium halide, and alkyl gallium halide (seeInternational Union of Pure and Applied Chemistry (IUPAC), version3,October 2005, for Group 13 metals of the periodic table). Other Lewisacid compounds besides those of Group 13 metals may also be used. In oneembodiment the first component is aluminum halide or alkyl aluminumhalide. For example, aluminum trichloride (AlCl₃) may be used as thefirst component for preparing the ionic liquid catalyst.

The second component making up the ionic liquid catalyst is an organicsalt or mixture of salts. These salts may be characterized by thegeneral formula Q+A−, wherein Q+ is an ammonium, phosphonium, boronium,oxonium, iodonium, or sulfonium cation and A− is a negatively chargedion such as Cl−, Br⁻, ClO₄ ⁻, NO₃ ⁻, BF₄ ⁻, BCl₄ ⁻, PF₆ ⁻, SbF₆ ⁻, AlCl₄⁻, Al₂Cl₇ ⁻, Al₃Cl₁₀ ⁻, ArF₆ ⁻, TaF₆ ⁻, CuCl₂ ⁻, FeCl₃ ⁻, SO₃CF₃ ⁻,SO₃C₇ ⁻, and 3-sulfurtrioxyphenyl. In one embodiment the secondcomponent is selected from those having quaternary ammonium halidescontaining one or more alkyl moieties having from about 1 to about 9carbon atoms, such as, for example, trimethylammonium hydrochloride,methyltributylammonium, 1-butyl pyridinium, or alkyl substitutedimidazolium halides, such as for example, 1-ethyl-3-methyl-imidazoliumchloride.

In one embodiment the ionic liquid catalyst is a quaternary ammoniumchloroaluminate ionic liquid having the general formula RR′ R″ N H⁺Al₂Cl₇ ⁻, wherein RR′ and R″ are alkyl groups containing 1 to 12carbons. Examples of quaternary ammonium chloroaluminate ionic liquidsalts are an N-alkyl-pyridinium chloroaluminate, anN-alkyl-alkylpyridinium chloroaluminate, a pyridinium hydrogenchloroaluminate, an alkyl pyridinium hydrogen chloroaluminate, adi-alkyl-imidazolium chloroaluminate, a tetra-alkyl-ammoniumchloroaluminate, a tri-alkyl-ammonium hydrogen chloroaluminate, or amixture thereof.

The presence of the first component should give the ionic liquid a Lewisor Franklin acidic character. Generally, the greater the mole ratio ofthe first component to the second component, the greater is the acidityof the ionic liquid mixture.

For example, a typical reaction mixture to prepare n-butyl pyridiniumchloroaluminate ionic liquid salt is shown below:

The molar ratio of Al to the heteroatom is greater than 2.0 when theacid catalyst is held at a temperature at or below 25° C. for at leasttwo hours.

In different embodiments the molar ratio of Al to the heteroatom isabout 5 or greater, about 10 or greater, about 50 or greater, or evengreater than 100. In some embodiments there is little or no heteroatom,so the molar ratio of Al to the heteroatom can be about 10 to about1000, or even higher.

The acid catalyst comprises greater than 15 wt % conjunct polymer. Thehigh level of conjunct polymer in the catalyst increases the catalyst'scapacity to uptake acids, such as AlCl₃. In different embodiments theacid catalyst comprises greater than 20 wt % conjunct polymer, greaterthan 25 wt % conjunct polymer, greater than 30 wt % conjunct polymer,greater than 40 wt % conjunct polymer, or greater than 50 wt % conjunctpolymer.

The contacting may occur at any temperature known to produce goodhydrocarbon conversion. These temperatures can range from about −20° C.up to about 500° C. For isoparaffin/olefin alkylation using an ionicliquid catalyst the temperature can range from about −20° C. up to about200° C. In different embodiments the temperature can be from −10° C. to100° C., from 0° C. to 50° C., or below 25° C.

In one embodiment the acid catalyst is made with reagents having nonitrogen-containing compounds.

In another embodiment the acid catalyst is made from at least oneconjunct polymer and a Lewis acid. AlCl₃ is one example of a usefulLewis acid. In yet another embodiment the acid catalyst is made from atleast one conjunct polymer, AlCl₃, and hydrogen chloride. The conjunctpolymer can comprise a halide. Examples of halides are fluorine,chlorine, bromine, iodine, and combinations thereof.

The level of conjunct polymer in the acid catalyst is determined byhydrolysis of known weights of the catalyst. An example of a suitabletest method is described in Example 3 of commonly assigned U.S. PatentPublication Number US20070142213A1. Conjunct polymers can be recoveredfrom the acid catalyst by means of hydrolysis. The hydrolysis recoverymethods employ procedures that lead to complete recovery of the conjunctpolymers and are generally used for analytical and characterizationpurposes because it results in the destruction of the catalyst.Hydrolysis of the acid catalyst is done, for example, by stirring thespent catalyst in the presence of excess amount of water followed byextraction with low boiling hydrocarbon solvents such as pentane orhexane. In the hydrolysis process, the catalyst salt and other saltsformed during hydrolysis go into the aqueous layer while conjunctpolymers go into the organic solvent. The low boiling solvent containingthe conjunct polymers are concentrated on a rotary evaporator undervacuum and moderate temperature to remove the extractant, leaving behindthe high boiling residual oils (conjunct polymers) which are collectedand analyzed. The low boiling extractants can be also removed bydistillation methods.

In one embodiment, the conjunct polymer is extractable. The conjunctpolymer may be extracted during a catalyst regeneration process, such asby treatment of the catalyst with aluminum metal or with aluminum metaland hydrogen chloride. Examples of methods for regenerating ionic liquidcatalysts are taught in U.S. Patent Publications US20070142215A1,US20070142213A1, US20070142676A1, US20070142214A1, US20070142216A1,US20070142211A1, US20070142217A1, US20070142218A1, US20070249485 A1, andin U.S. patent application Ser. No. 11/960319, filed Dec. 19, 2007; Ser.No. 12/003577, filed Dec. 28, 2007; Ser. No. 12/003578, filed Dec. 28,2007; Ser. No. 12/099486, filed Apr. 8, 2008; and 61/118215, filed Nov.26, 2008.

One advantage of the acid catalyst having a molar ratio of Al to aheteroatom selected from the group of N, P, O, S, and combinationsthereof greater than 2.0 is its ability to continue to functioneffectively to convert the hydrocarbon, without becoming significantlydeactivated by conjunct polymer. In this embodiment the acid catalystcan be used continuously without having to be removed from the reactorfor regeneration for more than 7 days, more than 25 days, or more than50 days. In this embodiment the acid catalyst may be regenerated inpart, such that only a portion of the acid catalyst is regenerated at atime and the hydrocarbon conversion process does not need to beinterrupted. For example, a slip stream of the acid catalyst effluentcan be regenerated and recycled to the hydrocarbon conversion reactor.In one embodiment the level of the conjunct polymer is maintained withinthe desired range by partial regeneration in a continuous hydrocarbonconversion process.

Examples of hydrocarbon conversions are alkylation, isomerization,hydrocracking, polymerization, dimerization, oligomerization, acylation,metathesis, copolymerization, hydroformylation, dehalogenation,dehydration, and combinations thereof. In one embodiment the hydrocarbonconversion is isoparaffin/olefin alkylation. Examples of ionic liquidcatalysts and their use for isoparaffin/olefin alkylation are taught,for example, in U.S. Pat. Nos. 7,432,408 and 7,432,409, 7,285,698, andU.S. patent application Ser. No. 12/184069, filed Jul. 31, 2008. Inanother embodiment the conversion of a hydrocarbon is alkylation ofparaffins, alkylation of aromatics, or combinations thereof.

In some embodiments the acid catalyst comprising greater than 15 wt %conjunct catalyst remains liquid, and does not precipitate significantamounts of solids when it is held for extended periods of time at 25° C.For example, in one embodiment the Lewis acid remains soluble in theacid catalyst, such that less than 0.5 wt %, less than 0.1 wt %, lessthan 0.05 wt %, less than 0.01 wt %, or zero wt % of the Lewis acid orother solid precipitates out of the liquid catalyst when it is held forthree hours or longer at 25° C. This provides a significant technicaladvantage over other ionic liquid catalysts that precipitate out solidsduring use.

The time the catalyst can be held at a temperature at or below 25° C.can be fairly lengthy. In general, the time is for greater than aminute, but it can be much longer, such as for greater than 5 minutes,for at least two hours, three hours or longer, more than 7 days up totwo weeks, more than 50 days, several months, or even up to a year.

Any term, abbreviation or shorthand not defined is understood to havethe ordinary meaning used by a person skilled in the art at the time theapplication is filed. The singular forms “a,” “an,” and “the,” includeplural references unless expressly and unequivocally limited to oneinstance.

All of the publications, patents and patent applications cited in thisapplication are herein incorporated by reference in their entirety tothe same extent as if the disclosure of each individual publication,patent application or patent was specifically and individually indicatedto be incorporated by reference in its entirety.

This written description uses examples to disclose the invention,including the best mode, and also to enable any person skilled in theart to make and use the invention. Many modifications of the exemplaryembodiments of the invention disclosed above will readily occur to thoseskilled in the art. Accordingly, the invention is to be construed asincluding all structure and methods that fall within the scope of theappended claims.

EXAMPLES Example 1

An ionic liquid catalyst based on n-butyl pyridinium chloroaluminate,having a molar ratio of Al to N of about 5 was prepared and tested asfollows: 10.8 g (81 mmoles) of AlCl₃ was combined with 5.0 ml (15mmoles) of n-butyl pyridinium chloroaluminate ionic liquid salt in 30 mlisopentane. 20 ml (180 mmoles) t-butyl chloride was added over a periodof 15 minutes. As the reaction proceeded, the hydrocarbon solutionboiled and the temperature dropped to about 2 to 5° C. After the t-butylchloride addition ended, the temperature started to climb back up. Mostof the added AlCl₃ was dissolved, although a small amount still remainedundissolved. An additional 10 ml isopentane was added and a GC samplerevealed that the hydrocarbon phases consisted of a mixture of saturatedisoalkanes predominantly in the C5 to C7 range. After stirring over theweekend, almost all the AlCl₃ was dissolved, and the acid catalyst phasecontained 24.6 wt % conjunct polymer.

5 ml of the conjunct polymer, prepared above, was cooled to 0° C. At t=0min., 25 ml of a cold (0° C.) solution of 3.6% 2-pentene in isopentanewas added and the mixture was stirred on an ice bath. GC samples of thehydrocarbon phase showed slow olefin conversion. After 15 minutes, about33 wt % of the olefin was converted. Following the addition of 30 mlgaseous hydrogen chloride (1.2 mmoles) the reaction rate increaseddramatically. After an additional 3 minutes, 100% of the olefin wasconverted. The hydrocarbon phase showed that the olefin conversion wasto predominantly C8 to C10 isoalkanes.

Example 2

A liquid acid catalyst made entirely of conjunct polymer, and having noheteroatom-containing compounds containing N, S, O, or P, was preparedand tested. This liquid acid catalyst had a molar ratio of Al toheteroatom selected from N, S, O, P, or combinations thereof muchgreater than 100.

14.2 g (106 mmoles) AlCl₃ was slurried up in 30 ml isopentane at roomtemperature in a flask. 45 ml (38 g, 410 mmoles) t-butyl chloride wasadded gradually over about half an hour. Gas evolution was observed. Thetemperature of the slurry in the flask dropped during addition. Withoutbeing bound by theory, it is expected that the temperature drop wascaused by evaporating hydrogen chloride and the formation of isobutenein the reaction. After the complete addition of the t-butyl chloride,the flask was allowed to warm back up to room temperature. At this pointthe flask contained a clear brown somewhat viscous liquid with a verysmall amount of clear hydrocarbon phase on top. The yield of the clearbrown somewhat viscous liquid was 31.9 g. The clear brown somewhatviscous liquid was analyzed and was found to contain 43.5 wt % conjunctpolymer. This clear brown somewhat viscous liquid was a conjunct polymerbased ionic liquid. Laboratory experience has shown that the conjunctpolymer prepared in this manner does not to any significant extentdiffer from the conjunct polymer formed in ionic liquid catalyzedisobutane alkylation.

5 ml of the conjunct polymer based ionic liquid described above wassaturated with hydrogen chloride at 1 atm pressure and reacted with 25ml of 5% 2-pentene in isopentane at 0° C. as described in Example 3.After 1.5 minutes the olefin conversion was 74 wt %, and after 3 minutesmore than 98 wt % of the olefin was converted. The reaction productcontained a substantial amount of C9-C11 alkylate. Initially, in thisexperiment, much of the reacted olefin was converted to a mixture of 2-and 3-pentyl chloride, which subsequently reacted to form the finalalkylate product.

Example 3

Two alkylation experiments using different ionic liquid catalysts wererun on the same feed, at the same temperature, and for the same lengthof time. The feed was isopentane and 2-pentenes; the temperature was 0°C.; and the time was 6 minutes. In one experiment the alkylationcatalyst was n-butyl pyridinium heptachlorodialuminate. In the secondexperiment the alkylation catalyst was the same conjunct polymer acidcatalyst as described in Example 2 (ASO.HAl2Cl7). The reaction productswere collected and analyzed by GC. The GC results are shown below.

Ionic Liquid: NBuPyAL2CL7 ASO.HAI2CI7 (Reference) Example 2 ReactionConditions: 6 min, 0° C. 6 min, 0° C. C6 15.44 22.85 C7 4.07 11.47 C83.35 5.79 C9 10.45 12.68 C10 33.36 32.10 C11+ 33.33 15.11

The yields and selectivity of the products were similar between the twoexperiments. Although the n-butyl pyridinium heptachlorodialuminatehydrocarbon conversion gave a slightly heavier product in thisparticular experiment, this can be controlled by the adjustment of thehydrogen chloride level during the reaction. The adjustment of thehydrogen chloride level to control product selectivity is described inU.S. patent application Ser. No. 12/233,481, filed Sep. 17, 2008.

1. An acid catalyst effective for a conversion of a hydrocarbon,comprising greater than 15 wt % halide-containing conjunct polymer, anda Lewis acid; wherein less than 0.1 wt % solid precipitates from thecatalyst when it is held for three hours or longer at 25° C. or below.2. The acid catalyst of claim 1, wherein the catalyst comprises greaterthan 25 wt % halide-containing conjunct polymer.
 3. The acid catalyst ofclaim 1, wherein the conversion is alkylation, isomerization,hydrocracking, polymerization, dimerization, oligomerization, acylation,acetylation, metathesis, copolymerization, dehalogenation, dehydration,olefin hydrogenation, or combinations thereof.
 4. The acid catalyst ofclaim 1, wherein at least about 33 wt % of the hydrocarbon is converted.5. The acid catalyst of claim 4, wherein at least 74 wt % of thehydrocarbon is converted.
 6. The acid catalyst of claim 1, additionallycomprising a hydrogen chloride.
 7. The acid catalyst of claim 1,additionally comprising a quaternary ammonium chloroaluminate ionicliquid.
 8. The acid catalyst of claim 1, wherein the Lewis acid isaluminum chloride.
 9. The acid catalyst of claim 1, wherein the acidcatalyst is a clear brown liquid.